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June 9, 2019 23:19
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| #include <stdio.h> | |
| #include <stdint.h> | |
| const unsigned char data[128] = { | |
| 0x02, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
| 0x00, 0x00, 0x00, 0x00, 0xFF, 0x00, 0x00, 0x00, 0xFF, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xEB, 0x66, 0x54, 0x11 | |
| }; | |
| // Crash 1 save sector checksum calculator; based on NSF Chunk Checksum Calculator | |
| uint32_t nsfChecksum(const unsigned char *data) | |
| { | |
| uint32_t checksum = 0x12345678; | |
| for (int i = 0;i < 128 /*65536*/;i++) | |
| { | |
| /*if (i < 12 || i >= 16)*/ | |
| if (i < 124) | |
| checksum += data[i]; | |
| checksum = checksum << 3 | checksum >> 29; | |
| } | |
| return checksum; | |
| } | |
| int main(void) | |
| { | |
| printf("CHECKSUM: %llX\n", (long long)nsfChecksum(data)); | |
| } |
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